Reloadable sheath for catheter system for deploying vasoocclusive devices

ABSTRACT

The introducer sheath can be loaded onto a vasoocclusive device after removal of the vasoocclusive device from a microcatheter, to permit the vasoocclusive embolic coil assembly to be used again during a clinical procedure. The sheath includes a hollow, elongated tubular member with a longitudinal slot formed in the upper wall of the elongated tubular member and extending along the length of elongated tubular member. The upper wall of the elongated tubular member adjacent to the slot has an angled configuration to accept the vasoocclusive device. The sheath may include wing members extending outwardly from the angled configuration on the outside surface of the hollow, elongated tubular member to facilitate insertion of the vasoocclusive device into the sheath. The elongated tubular member may also consist of a segment with no slot attached to a flexible pusher member to facilitate initiation of loading of the vasoocclusive device into the sheath.

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to devices for interventionaltherapeutic treatment or vascular surgery for treatment of defects inthe vasculature, and more particularly concerns a system and method fordelivering intravascular interventional devices, such as for treatmentof aneurysms.

[0002] Vascular interventional devices such as vasoocclusive devices aretypically placed within the vasculature of the human body by use of acatheter. Vascular interventional devices such as stents can be placedwithin an occluded vessel to facilitate blood flow through the vessel,and vasoocclusive devices are typically either placed within a bloodvessel to block the flow of blood through a vessel making up thatportion of the vasculature through the formation of an embolus, or areplaced within an aneurysm stemming from the vessel to form such anembolus within the aneurysm. Stents can have a wide variety ofconfigurations, but generally need to be placed and then released at adesired location within a blood vessel. Vasoocclusive devices used forthese procedures can also have a wide variety of configurations, andaneurysms have been treated with external surgically placed clips,detachable vasoocclusive balloons and embolus generating vasoocclusivedevices such as one or more vasoocclusive or embolic coils.

[0003] The delivery of such vasoocclusive devices has typically beenaccomplished by a variety of means, including via a catheter in whichthe device is pushed through an opening at the distal end of thecatheter by a pusher to deploy the device. The vasoocclusive devices canbe produced in such a way that they will pass through the lumen of acatheter in a linear shape and take on a complex shape as originallyformed after being deployed into the area of interest, such as ananeurysm.

[0004] Detachable vasoocclusive devices are typically embolic coilsfixed to a distal end of a flexible pusher member for delivery of theembolic coils, and may be detached mechanically, electrically or by someother means from the flexible pusher member at the target location. Thedetachable embolic coils can be delivered to the target location anddetached if correctly sized and positioned, or may be withdrawn withoutbeing detached if the coils are not correctly sized, are not correctlypositioned, or microcatheter positioning is lost. Some availablevasoocclusive devices are not reused during a patient procedure if theyare removed during the procedure, due to the inability to reload thedevice into the microcatheter. It would be desirable to provide a systemand method for reusing vasoocclusive devices during a clinical procedureafter removal from a microcatheter introducer. The present inventionmeets these and other needs.

SUMMARY OF THE INVENTION

[0005] Briefly, and in general terms, the present invention provides foran introducer sheath for vasoocclusive devices that can be loaded onto avasoocclusive embolic coil assembly after removal of the vasoocclusiveembolic coil assembly from a microcatheter, to permit reuse of thevasoocclusive embolic coil assembly during a clinical procedure and tominimize the loss of an otherwise acceptable vasoocclusive embolic coilproduct.

[0006] The present invention accordingly provides for a sheath for atherapeutic vasoocclusive device which includes an assembly of aflexible pusher member and an embolic coil. The sheath includes ahollow, elongated tubular member having opposing upper and lower walls,opposing side walls, and a longitudinal interior channel, and alongitudinal slot formed in the upper wall of the elongated tubularmember and extending the length, or majority of the length, of elongatedtubular member. The slot has opposing sides with inner side surfacesextending through the upper wall of the elongated tubular member leadingto the interior channel permitting introduction of the vasoocclusivedevice into the interior channel. In one aspect, the upper wall of theelongated tubular member adjacent to the slot has an angledconfiguration on the outside surface of the hollow, elongated tubularmember. The angled configuration on the outside surface of the hollow,elongated tubular member has opposing exterior surfaces forming aninterior angle of typically about 110° to 150°.

[0007] In another aspect, the lower wall of the hollow, elongatedtubular member is about 0.002 to 0.004 inches thick to allow theopposing sides of the slot of the hollow, elongated tubular member toflex outwardly to allow the slot to open to accept the vasoocclusivedevice. The hollow, elongated tubular member may be formed from athermoplastic material, such as high density polyethylene, for example.

[0008] In one embodiment, the sheath may further include wing membersextending outwardly from the angled configuration on the outside surfaceof the hollow, elongated tubular member to facilitate insertion of thevasoocclusive device into the sheath. The wing members of the angledconfiguration on the outside surface of the hollow, elongated tubularmember have opposing exterior surfaces typically forming an interiorangle of about 110° to 150°. In a variation of these embodiments, thesheath may be formed in combination with the vasoocclusive device, theelongated tubular member consisting of a length with no slot attached toa segment of the flexible pusher member to facilitate initiation ofloading of the flexible pusher member and embolic coil into the sheath.

[0009] These and other aspects and advantages of the invention willbecome apparent from the following detailed description and theaccompanying drawings, which illustrate by way of example the featuresof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a perspective view of a first embodiment of thereloadable sheath for a vasoocclusive device, according to the presentinvention.

[0011]FIG. 2 is a perspective view of a second embodiment of thereloadable sheath for a vasoocclusive device, according to the presentinvention.

[0012]FIG. 3 is a cross-sectional view illustrating dimensions of thereloadable sheath of FIG. 1.

[0013]FIG. 4 is a longitudinal sectional view of a third embodiment ofthe reloadable sheath in combination with a vasoocclusive devicepermanently attached to an end of the reloadable sheath, showing thevasoocclusive device substantially unloaded from the reloadable sheath.

[0014]FIG. 5 is a longitudinal sectional view of the reloadable sheathof FIG. 4, showing the vasoocclusive device fully loaded into thereloadable sheath.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A reloadable sheath 10 for a therapeutic vasoocclusive device 12.The vasoocclusive device typically includes an assembly of a flexiblepusher member 14 and an embolic coil 16 (only a portion of which isshown) attached to the flexible pusher member, as illustrated in FIGS. 5and 6. The flexible pusher member may, for example, include an elongatedoptical fiber having a distal end 18 sheathed in a tubular collar 20 ofshape memory material for retaining the embolic coil on the distal endof the flexible pusher member. The optical fiber can be sized to bequite flexible and bend sufficiently to follow the body lumen.Alternatively, the elongated pusher can be formed of suitable materialsfor conducting energy, such as radio frequency energy, magnetic energy,electrical energy, or ultrasonic energy, such as an elongated metalmember, for example, or of a heat pipe for conducting heat from a heatsource. Alternatively, the flexible pusher can consist of a tubular orsolid wire construction with attachment to an embolic coil to allow, forexample, deployment by mechanical or hydraulic means.

[0016] The reloadable sheath is generally formed of a hollow, elongatedtubular member 22 having an upper wall 24 and an opposing lower wall 26,opposing side walls 28 and 30, and a longitudinal interior channel 32.The upper wall of the elongated tubular member includes a slot 34 orslit with opposing interior sides 36 having surfaces extending throughthe upper wall leading to the interior channel, permitting introductionof the vasoocclusive device into the interior channel. The reloadablesheath may have the exemplary dimensions illustrated in FIGS. 3 and setforth in the table below. In the table, “A” indicates a possiblelongitudinal interior channel dimension (32) and “B” indicates apossible outer diameter sheath dimension. System “A” (in.) “B” (in.) 100.016 0.030 18 0.020 0.034

[0017] As is best seen in FIGS. 1 and 3 the upper wall of the elongatedtubular member adjacent to the slot typically has an outer angled orV-shaped configuration on the outside surface of the tubing, tofacilitate loading of the vasoocclusive device into the reloadablesheath. The slot may, for example, have opposing exterior surfacesforming an interior angle of about 110° to 150°. The lower wall of thetubing is typically about 0.002 to 0.004 inches thick to allow opposingsides of the slot of the hollow, elongated tubular member to flexoutwardly to allow the slot to open to accept the vasoocclusive device.The configuration allows the flexible pusher member to be inserted intothe reloadable sheath by positioning the flexible pusher member andembolic coil assembly over the slot and providing a sliding pressure,such as by a person's thumb, along the length of the flexible pushermember and embolic coil assembly to introduce the flexible pusher memberand embolic coil assembly into the sheath. In this embodiment, thesheath is fully removable from the flexible pusher member.

[0018] With reference to FIG. 2, in a second embodiment, the presentinvention provides for a reloadable sheath 10′ for a therapeuticvasoocclusive device 12, which typically includes an assembly of aflexible pusher member 14 and an embolic coil 16 described above andillustrated in FIGS. 4 and 5. The reloadable sheath 10′ is generallyformed of a hollow, elongated tubular member 22′ having an upper wall24′ and an opposing lower wall 26′, opposing side walls 28′ and 30′, anda longitudinal interior channel 32′. The upper wall of the elongatedtubular member includes a slot 34′ with opposing interior sides 36′having surfaces extending through the upper wall leading to the interiorchannel, permitting introduction of the vasoocclusive device into theinterior channel.

[0019] The upper wall of the elongated tubular member adjacent to theslot typically has an outer angled or V-shaped configuration on theoutside surface of the tubing, to facilitate loading of thevasoocclusive device into the reloadable sheath. The slot may, forexample, have opposing exterior surfaces forming an interior angle ofabout 110° to 150°. The lower wall of the tubing is typically about0.002 to 0.004 inches thick to allow opposing sides of the slot of thehollow, elongated tubular member to flex outwardly to allow the slot toopen to accept the vasoocclusive device. In this embodiment, the upperangled surface portions of the upper wall of the elongated tubularmember adjacent to the slot may be formed as outwardly extending wallsor wing members 38 to facilitate insertion of the flexible pusher memberand embolic coil assembly into the slotted sheath.

[0020] With reference to FIGS. 4 and 5, in a variation of the firstembodiment, which is equally applicable to the second embodiment, theinvention provides for a sheath in combination with a vasoocclusivedevice which includes an assembly of the flexible pusher member 14 andan embolic coil 16 that is adapted to be inserted into a portion of avasculature for occluding a portion of the vasculature for use ininterventional therapy and vascular surgery. The sheath can remainattached to a segment 40 of the flexible pusher member to facilitateinitiation of loading of the flexible pusher member into the sheath. Thesheath can be pulled off along the slot until the segment of the sheathwithout a slot is reached, a segment of length less than the unusedworking length of the pusher when fully loaded into the microcatheter,for example, about 10 cm.. The sheath can then be looped and leftattached to the end of the flexible pusher member while the flexiblepusher member is loaded into a microcatheter (not shown). If theflexible pusher member is removed without embolic coil detachment, thesheath can be loaded back onto the flexible pusher member starting atthe connected location and progressing toward an end of the flexiblepusher member. The sheath can then be advanced over the embolic coil toallow the embolic coil to be advanced into the microcatheter at a latertime.

[0021] In each of the foregoing embodiments, the elongated tubularmember forming the reloadable sheath is typically formed from athermoplastic material. The tubing may be formed from a thermoplasticmaterial such as high density polyethylene, for example. Alternatively,other similar polymeric materials may also be suitable, such aspolyurethane, nylons, polyetheretherketone (PEEK),polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), andthe like.

[0022] It will be apparent from the foregoing that while particularforms of the invention have been illustrated and described, variousmodifications can be made without departing from the spirit and scope ofthe invention. Accordingly, it is not intended that the invention belimited, except as by the appended claims.

What is claimed is:
 1. A sheath for a therapeutic vasoocclusive device,the vasoocclusive device including an assembly of a flexible pushermember and an embolic coil, the sheath comprising: a hollow, elongatedtubular member having opposing upper and lower walls, opposing sidewalls, and a longitudinal interior channel; and a longitudinal slotformed in the upper wall of the elongated tubular member and extendingthe length of elongated tubular member, the slot having opposing sideswith inner side surfaces extending through the upper wall of theelongated tubular member leading to the interior channel permittingintroduction of the vasoocclusive device into the interior channel. 2.The sheath of claim 1, wherein the upper wall of the elongated tubularmember adjacent to the slot has an angled configuration on the outsidesurface of the hollow, elongated tubular member.
 3. The sheath of claim2, wherein the angled configuration on the outside surface of thehollow, elongated tubular member has opposing exterior surfaces formingan interior angle of about 110° to 150°.
 4. The sheath of claim 1,wherein the lower wall of the hollow, elongated tubular member is about0.002 to 0.004 inches thick to allow the opposing sides of the slot ofthe hollow, elongated tubular member to flex outwardly to allow the slotto open to accept the vasoocclusive device.
 5. The sheath of claim 1,wherein the hollow, elongated tubular member is formed from athermoplastic material.
 6. The sheath of claim 1, wherein the hollow,elongated tubular member is formed from a high density polyethylene. 7.The sheath of claim 2, further comprising wing members extendingoutwardly from the angled configuration on the outside surface of thehollow, elongated tubular member to facilitate insertion of thevasoocclusive device into the sheath.
 8. The sheath of claim 7, whereinthe wing members of the angled configuration on the outside surface ofthe hollow, elongated tubular member have opposing exterior surfacesforming an interior angle of about 110° to 150°.
 9. A sheath for atherapeutic vasoocclusive device, the vasoocclusive device including anassembly of a flexible pusher member and an embolic coil, the sheathcomprising: a hollow, elongated tubular member having opposing upper andlower walls, opposing side walls, and a longitudinal interior channel; alongitudinal slot formed in the upper wall of the elongated tubularmember and extending the length of elongated tubular member, the slothaving opposing sides with inner side surfaces extending through theupper wall of the elongated tubular member leading to the interiorchannel permitting introduction of the vasoocclusive device into theinterior channel, wherein the upper wall of the elongated tubular memberadjacent to the slot has an angled configuration on the outside surfaceof the hollow, elongated tubular member.
 10. The sheath of claim 9,wherein the angled configuration on the outside surface of the hollow,elongated tubular member has opposing exterior surfaces forming aninterior angle of about 110° to 150°.
 11. The sheath of claim 9, whereinthe lower wall of the hollow, elongated tubular member is about 0.002 to0.004 inches thick to allow the opposing sides of the slot of thehollow, elongated tubular member to flex outwardly to allow the slot toopen to accept the vasoocclusive device.
 12. The sheath of claim 9,wherein the hollow, elongated tubular member is formed from athermoplastic material.
 13. The sheath of claim 9, wherein the hollow,elongated tubular member is formed from a high density polyethylene. 14.The sheath of claim 9, further comprising wing members extendingoutwardly from the angled configuration on the outside surface of thehollow, elongated tubular member to facilitate insertion of thevasoocclusive device into the sheath.
 15. The sheath of claim 14,wherein the wing members of the angled configuration on the outsidesurface of the hollow, elongated tubular member have opposing exteriorsurfaces forming an interior angle of about 110° to 150°.
 16. A sheathin combination with a vasoocclusive device, the vasoocclusive deviceincluding an assembly of a flexible pusher member and an embolic coilthat is adapted to be inserted into a portion of a vasculature foroccluding a portion of the vasculature for use in interventional therapyand vascular surgery, the sheath comprising: a hollow, elongated tubularmember having opposing upper and lower walls, opposing side walls, and alongitudinal interior channel, and a longitudinal slot formed in theupper wall of the elongated tubular member and extending most of thelength of elongated tubular member, leaving up to about 10 cm with noslot, the slot having opposing sides with inner side surfaces extendingthrough the upper wall of the elongated tubular member leading to theinterior channel permitting introduction of the vasoocclusive deviceinto the interior channel.
 17. The sheath of claim 16, wherein the upperwall of the elongated tubular member adjacent to the slot has an angledconfiguration on the outside surface of the hollow, elongated tubularmember.
 18. The sheath of claim 17, wherein the angled configuration onthe outside surface of the hollow, elongated tubular member has opposingexterior surfaces forming an interior angle of about 110° to 150°. 19.The sheath of claim 16, wherein the lower wall of the hollow, elongatedtubular member is about 0.002 to 0.004 inches thick to allow theopposing sides of the slot of the hollow, elongated tubular member toflex outwardly to allow the slot to open to accept the vasoocclusivedevice.
 20. The sheath of claim 16, wherein the hollow, elongatedtubular member is formed from a thermoplastic material.
 21. The sheathof claim 16, wherein the hollow, elongated tubular member is formed froma high density polyethylene.
 22. The sheath of claim 17, furthercomprising wing members extending outwardly from the angledconfiguration on the outside surface of the hollow, elongated tubularmember to facilitate insertion of the vasoocclusive device into thesheath.
 23. The sheath of claim 22, wherein the wing members of theangled configuration on the outside surface of the hollow, elongatedtubular member have opposing exterior surfaces forming an interior angleof about 110° to 150°.
 24. A sheath in combination with a vasoocclusivedevice, the vasoocclusive device including an assembly of a flexiblepusher member and an embolic coil that is adapted to be inserted into aportion of a vasculature for occluding a portion of the vasculature foruse in interventional therapy and vascular surgery, the sheathcomprising: a hollow, elongated tubular member having opposing upper andlower walls, opposing side walls, and a longitudinal interior channel,and a longitudinal slot formed in the upper wall of the elongatedtubular member and extending most of the length of elongated tubularmember, leaving up to about 10 cm with no slot, the slot having opposingsides with inner side surfaces extending through the upper wall of theelongated tubular member leading to the interior channel permittingintroduction of the vasoocclusive device into the interior channel,wherein the upper wall of the elongated tubular member adjacent to theslot has an angled configuration on the outside surface of the hollow,elongated tubular member.
 25. The sheath of claim 24, wherein the angledconfiguration on the outside surface of the hollow, elongated tubularmember has opposing exterior surfaces forming an interior angle of about110° to 150°.
 26. The sheath of claim 24, wherein the lower wall of thehollow, elongated tubular member is about 0.002 to 0.004 inches thick toallow the opposing sides of the slot of the hollow, elongated tubularmember to flex outwardly to allow the slot to open to accept thevasoocclusive device.
 27. The sheath of claim 24, wherein the hollow,elongated tubular member is formed from a thermoplastic material. 28.The sheath of claim 24, wherein the hollow, elongated tubular member isformed from a high density polyethylene.
 29. The sheath of claim 24,further comprising wing members extending outwardly from the angledconfiguration on the outside surface of the hollow, elongated tubularmember to facilitate insertion of the vasoocclusive device into thesheath.
 30. The sheath of claim 29, wherein the wing members of theangled configuration on the outside surface of the hollow, elongatedtubular member have opposing exterior surfaces forming an interior angleof about 110° to 150°.